Demi Knight Clark, a 36-year-old from South Carolina, believed she had an angel running with her Monday in the Boston Marathon.

She was just a few feet from the finish line when two explosive devices detonated. She probably would have been closer to the blasts that killed three and injured more than 140 if not for the fact her husband and two young daughters were in the VIP bleachers on the other side of the road.

Clark, who has worked as a PR rep in NASCAR in recent years, earned the VIP passes by raising money for a Boston charity. She shudders at the thought that if not for that, her family would have been on the side where the explosions occurred.

“They would have been right there to watch the finish,” she said. “Between that and having the angel on my shoulder of moving to the right so I could wave at my daughters because I really wanted them to see me finish, I was right there (and OK).

“I looked to my left and a lot of the runners around me were on the ground. It was surreal.”

Clark's PR agency, Girl Friday PR, has represented such NASCAR teams at ThorSport Racing, which competes in the Camping World Truck Series. She represented such drivers as Matt Crafton and Johnny Sauter.

For about a half-hour afterward the marathon, Clark said she couldn’t hear anything because of the noise from the blast.

“We didn’t know what happened on the first (blast),” Clark said. “Then the second one went off simultaneously, and I thought we were under attack.

“My instant thought was, ‘Oh, good God, the bleachers could light up or these could go right down the line.’ It was sheer panic.”

Like many runners, Clark was aiming for a time of four hours, and she said she wouldn’t be surprised if the blasts were timed to coincide with the heavy flow of runners who finish at that time. A photo shows the race timer at 4:09 as the blasts went off and Clark approaching the finish line.

“I crossed (the line) and didn’t actually see it,” Clark said. “But the official next to me, I looked at him as it went off and he had a look of horror on his face.

“I was like, ‘What just happened?’ No cannon is going off at the 4-hour mark. It was just crazy.”

Clark, who has run in three marathons, decided to do the Boston Marathon and raise funds for “Dream Big!,” a Boston charity that helps low-income girls get sports gear. Her fundraising efforts earned her the passes that her husband and daughters used to sit in the fifth row of the bleachers.

After the blasts, Clark turned around and got to them amid the chaos before trying to scramble away from the area.

“I saw the second blast and I instantly looked over to see where they were—they were maybe 100 yards from me,” Clark said. “The official was trying to get me to go through the chute and I was like, ‘No, no, no, I’m going to get my family.’

“At the time, people thought more (explosions) were going to go off. It was just absolutely chaos.”

Clark said her two girls, ages 7 and 9, were traumatized by the tragedy.

“They don’t understand why this would happen at a running event,” she said. “It blew out all the glass and there were so many bloody people. The scene was just horrific.”

She said that because she had nothing to drink after finishing, she nearly went into shock. A family gave her some water.

“I don’t feel like I ran 26 miles today,” Clark said. “I’m just watching coverage and thinking how horrific this is for the running community and the families.

“There were people behind me, their families were there to support (them). They rerouted the finish and someone had to get rerouted and found out later that their family was hurt or even worse. That breaks my heart.”

Clark said that marathons mean so much to the runners, especially those who raise money for charity, and that what should have been a day of joy turned into heartbreak.

“I definitely feel an angel on my shoulder of some sort because I was moving to the right and being in the right place (not to get hurt) and my kids being OK, but at the same time I feel guilt,” Clark said.

“Other people aren’t all right. You can’t celebrate a finish. I had a wonderful race and talked to so many lovely people. But that’s totally irrelevant at this point because people are hurt.”